GPS Power-Up: Get Ready for New Sense of Place

Photo courtesy: Boeing

The global positioning system works fine if you’re trying to persuade your phone to point you to the nearest bar or untangle a freeway interchange. But it’s not exactly accurate — GPS can be off by 15 feet or more, and the signal degrades when confronted with tall buildings and trees. It even gets screwed up by the slightest electromagnetic interference, like stray radio waves or storms in the ionosphere.

Hopefully this will soon be a distant memory. In May the Air Force will begin launching the so-called IIF generation of GPS satellites, which will eventually replace half the existing armada. The new birds each transmit three civilian GPS signals — we’ve typically been making do with just one for years — including a military-strength transmission that should enable autopilots to land with zero visibility. A three-signal world will mean always-on GPS that’s accurate to within 3 feet, even indoors and in concrete urban canyons. Forget finding the bar; you’ll be able to geolocate your stool.